The present invention relates to the field of medical imaging, and in particular to an imaging technique for an X-ray medical image.
There are many factors impacting the imaging quality of an X-ray medical image, among which X-ray scattering is one of the most important factors. FIG. 1 shows scattered rays generated in an X-ray imaging system, wherein part of the scattered rays are generated from the X-rays emitted from the X-ray tube out of the focal spot (1). These scattered rays make up 25% of the rays originally emitted from the X-ray tube. If these rays cannot be effectively filtered, the patient will be radiated more than necessary, and the imaging quality will be impacted. In at least some current X-ray medical image devices, rays from the X-ray tube all penetrate the patient's body (3) after passing through the collimator (2) and being subjected to beam hardening. Before reaching the detector, the scattered rays among the X-rays are filtered by a grid. Before the X-rays penetrating the body (3), however, a significant amount of scattered rays of the X-rays are not filtered in any way. On the other hand, the dimension of the scattering angle also has a great influence on the X-ray imaging quality. FIG. 1 shows the X-ray scattering angle Φ (4). The optimum condition is achieved when Φ=90°. When Φ>90°, a larger Φ means that more rays from the X-ray source will scatter to deviate from the direction of the original rays. In at least some known current X-ray medical image devices, the scattering angle Φ is greater than 90° and is very large, even if a collimator (2) is used. Due to the above two phenomena, at least some current X-ray medical image devices will generate more scattered X-rays in application, which not only affects the image quality but also subjects the patient to more radiation than is necessary.